Percolation experiment instrument

Abstract

The utility model discloses a percolation experiment instrument which comprises a mother board A and a mother board B. The mother board A is provided with a circular hole array, each circular hole of the circular hole array is embedded with a photoresistor, the photoresistors are connected through wires to form a photoresistor network, and the photoresistor network is electrically connected to a photoresistor main loop. A direct-current power supply, a sampling resistor, a current sudden change detection circuit and an ampere meter are arranged in a main loop of the photoresistor; a round hole array consistent with the mother board A is arranged on the mother board B, and a light-emitting diode is embedded in each round hole on the mother board B to form a light-emitting diode array; the two mother boards are attached together, so that the round holes of the round hole array of the mother board A are opposite to the round holes of the round hole array of the mother board B in a one-to-one mode. According to the percolation experiment instrument, experiments can be carried out in different light environments, and an operator can know the practical significance of the percolation theory through the processes of practical manual experiments, data recording, subsequent data processing and the like.

Description

Technical Field

[0001] The utility model belongs to the technical field of experimental instruments, and in particular relates to a percolation experimental instrument. Background Art

[0002] Percolation theory is one of the commonly used theoretical methods for dealing with strongly disordered systems and systems with random geometric structures. The central content of this theoretical research is that when the composition of the system or the density change in a certain sense reaches a certain value (called the percolation threshold), some physical properties of the system will change sharply at the percolation threshold, that is, at the percolation threshold, the continuity of some physical phenomena of the system will change, such as suddenly disappearing or suddenly appearing.

[0003] Percolation transition refers to the sudden appearance (or disappearance) of a long-range connection in a large disordered system, as the degree of connection, or a certain density, occupancy number, or concentration increases (or decreases) to a certain extent. This is called a percolation transition, or a sharp phase transition. It is this percolation transition that makes it a natural model for describing a variety of different phenomena and is used to explain some of the most important physical concepts of phase transitions and critical phenomena.

[0004] Assume that there is a square grid with N rows and N columns arranged at equal intervals, connected to each other at the intersections, that is, a large square contains several small squares of the same size. If a proper amount of DC voltage is applied to one of the opposite sides of the square grid, then current will flow between the opposite sides of the square grid. If the edges of the small squares are randomly cut with scissors, the number of cut edges is small at the beginning, and the entire grid still has current flowing. As the number of cuts increases, the current gradually decreases until a certain number of cuts is reached, and the current of the entire network suddenly decreases sharply or disappears. At this time, it is said that a percolation phase transition has occurred. This process is the simplest phase transition. Therefore, the above square grid model is a typical model for studying phase transitions and critical phenomena. This model belongs to bond percolation. As the value of the bond (edge) connection probability p gradually decreases from 1, the grid will undergo a percolation phase transition when p = 0.5, so p = 0.5 is also called the percolation threshold Pc.

[0005] Percolation theory has been applied to analytical research in various fields and is an effective theoretical tool, so it is of great significance. The development of experimental instruments based on this theory will help to understand and apply the percolation theory. The utility model patent with the published patent number "ZL202121447504.X" is a design based on the bond percolation model, but the design of the percolation experimental instrument is only suitable for ideal ambient light. When the light is insufficient, the use effect of the instrument will be affected. In addition, the instrument only uses small balls to occupy the holes to block the photoresistor. The experimental method is relatively simple, and several groups of experiments need to be carried out each time. The number of small balls needs to be accurately counted during the experiment, and the number of small balls needs to be adjusted according to different occupation probabilities. In addition, the small balls may fall and be lost, so the experimental efficiency is low. This patent can optimize the above problems and expand the operation mode and usage scenarios of the experimental instrument. The instrument is easy to operate and the experimental efficiency can be further improved. Utility Model Content

[0006] The utility model aims to overcome the deficiencies of the prior art and provide a percolation test instrument.

[0007] The utility model is realized by the following technical solutions:

[0008] A percolation tester, comprising a motherboard A and a motherboard B, wherein a circular hole array is arranged on the motherboard A, wherein each circular hole of the circular hole array is embedded with a photoresistor, and the photoresistors are connected by wires to form a photoresistor network, wherein the photoresistor network is electrically connected to a photoresistor main circuit, wherein a DC power supply, a sampling resistor and a current sudden change detection circuit are arranged in the photoresistor main circuit, wherein the current sudden change detection circuit is connected in parallel at both ends of the sampling resistor, and is used to detect whether a current sudden drop occurs in the photoresistor network;

[0009] A circular hole array consistent with that of the motherboard A is arranged on the motherboard B, and a light emitting diode is embedded in each circular hole on the motherboard B. These light emitting diodes are electrically connected to a printed circuit board to form a light emitting diode array. The light emitting diode array is electrically connected to a light emitting diode array control circuit, and the light emitting diode array control circuit controls the on and off state of each light emitting diode in the light emitting diode array;

[0010] The front side of motherboard A and the front side of motherboard B are attached together, so that each circular hole of the circular hole array of motherboard A is opposite to each circular hole of the circular hole array of motherboard B one by one.

[0011] In the above technical solution, the front surface of the motherboard A and the front surface of the motherboard B are both smooth planes, so that the front surface of the motherboard A and the front surface of the motherboard B can be closely attached together, and each circular hole of the circular hole array of the motherboard A is opposite to each circular hole of the circular hole array of the motherboard B one by one; and because the two motherboards are closely attached together, no light leaks between the circular holes of the two motherboards.

[0012] In the above technical solution, the circular hole array is a circular hole formed in the middle of each side of each small square in a square grid of N rows and N columns.

[0013] In the above technical solution, the photoresistor network is a square grid with N rows and N columns, and a photoresistor is connected in series at the middle position of each side of each small square in the square grid.

[0014] In the above technical solution, a power switch and an ammeter are provided in the photoresistor main circuit, the power switch is used to control the on and off of the photoresistor main circuit, and the ammeter is used to detect the current of the photoresistor main circuit.

[0015] In the above technical solution, an indicating light emitting diode is provided in the current sudden change detection circuit for indicating the status of the current change.

[0016] In the above technical solution, the current sudden change detection circuit includes a comparator, a resistor R1, a resistor R2, a resistor R3 and an indicator light emitting diode, one end of the sampling resistor is connected to the inverting input terminal of the comparator, the other end of the sampling resistor is connected to the GND terminal of the comparator, the resistor R1 and the resistor R2 are connected in series between the VCC terminal and the GND terminal of the comparator, and the connection point between the resistor R1 and the resistor R2 is connected to the in-phase input terminal of the comparator, and the resistor R3 and the indicator light emitting diode are connected in series between the VCC terminal and the output terminal of the comparator. The sampling resistor is used to sample the current signal of the photoresistor network, and the sampling voltage at both ends of the sampling resistor will be compared with the reference voltage of the in-phase input terminal of the comparator. When the current of the photoresistor network drops suddenly, the sudden decrease of the current triggers the change of the comparator in the current sudden change detection circuit, and the indicator light emitting diode in the current sudden change detection circuit changes from the original on-state to the off-state, thereby indicating whether the current of the photoresistor network drops suddenly through the on-off state of the indicator light emitting diode.

[0017] In the above technical solution, the connecting wires of the photoresistor network are adhered to the back of the motherboard A through organic silicone; a bottom plate is also provided on the back of the photoresistor network to protect the photoresistor network and stably fix the photoresistor network on the motherboard A.

[0018] In the above technical solution, the light-emitting diode array control circuit includes a single-chip microcomputer and M serial / parallel output shift registers, the single-chip microcomputer is connected to the serial / parallel output shift registers, the M serial / parallel output shift registers are cascaded with each other, and each parallel output end of the serial / parallel output shift register is connected to a light-emitting diode in the light-emitting diode array through a resistor, thereby controlling the lighting of each light-emitting diode in the light-emitting diode array.

[0019] In the above technical solution, a power switch is provided in the light emitting diode array control circuit to control the on and off of the light emitting diode array control circuit.

[0020] The advantages and beneficial effects of the utility model are:

[0021] The percolation experiment instrument of the utility model has reasonable design and is easy to operate. Experiments can be carried out in different light environments, which expands the application scenarios. Through actual hands-on experiments, data recording and subsequent data processing, the operator can recognize the practical significance of the percolation theory and contribute to the understanding of relevant theoretical knowledge. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a motherboard A of a percolation tester of the present utility model.

[0023] Figure 2 It is a structural schematic diagram of a motherboard B of a percolation tester of the present invention.

[0024] Figure 3 It is a schematic diagram of the overall structural principle of the percolation test instrument of the utility model.

[0025] Figure 4 This is a circuit diagram of the light emitting diode array control circuit in the utility model, which only takes 16 light emitting diodes as an example and can be expanded according to the situation.

[0026] Figure 5 The utility model is a circuit diagram of a current sudden change detection circuit.

[0027] For ordinary technicians in this field, other relevant drawings can be obtained based on the above drawings without any creative work. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the technical solution of the present utility model, the technical solution of the present utility model is further described below in conjunction with specific embodiments.

[0029] A percolation tester comprises two motherboards, namely, motherboard A and motherboard B. Motherboard A and motherboard B are preferably rectangular plates of the same size, and both motherboards are made of opaque materials.

[0030] See attached Figure 1 , a circular hole array is arranged on the motherboard A, each circular hole is embedded with a photoresistor, and the photoresistors are connected by wires to form a photoresistor network. A pair of opposite sides of the photoresistor network each lead out a wire and connect to the photoresistor main circuit; a DC power supply, a sampling resistor and a current sudden change detection circuit are arranged in the photoresistor main circuit. The current sudden change detection circuit is connected in parallel at both ends of the sampling resistor to detect whether the current of the photoresistor network drops suddenly. For details, see the attached Figure 5 The current sudden change detection circuit includes a comparator (model LM339), a resistor R1, a resistor R2, a resistor R3 and an indicator light emitting diode D1. One end e of the sampling resistor is connected to the inverting input end of the comparator, and the other end g of the sampling resistor is connected to the GND end of the comparator. The resistor R1 and the resistor R2 are connected in series between the VCC end and the GND end of the comparator, and the connection point between the resistor R1 and the resistor R2 is connected to the in-phase input end of the comparator. The resistor R3 and the indicator light emitting diode D1 are connected in series between the VCC end and the output end of the comparator. The sampling resistor is used to sample the current signal of the photoresistor network. The sampling voltage at both ends of the sampling resistor will be compared with the reference voltage at the in-phase input end of the comparator. When the current of the photoresistor network drops suddenly, the sudden decrease of the current triggers the change of the comparator in the current sudden change detection circuit. The indicator light emitting diode D1 in the current sudden change detection circuit changes from the original on-state to the off-state, thereby indicating whether the current of the photoresistor network drops suddenly through the on-off state of the indicator light emitting diode D1.

[0031] Furthermore, a power switch is provided in the main circuit of the photoresistor for controlling the on and off of the main circuit of the photoresistor; an ammeter is provided in the main circuit of the photoresistor for detecting the current size of the main circuit of the photoresistor.

[0032] Furthermore, the connecting wires of the photoresistor network are adhered to the back of the motherboard A through organic silicone; a bottom plate is also provided on the back of the photoresistor network to protect the photoresistor network and stably fix the photoresistor network on the motherboard A, that is, the motherboard A and the bottom plate sandwich the photoresistor network in the middle.

[0033] See attached Figure 2 , a circular hole array consistent with that of motherboard A is arranged on motherboard B, a light emitting diode is embedded in each circular hole on motherboard B, these light emitting diodes are electrically connected to a printed circuit board to form a light emitting diode array, and the printed circuit board is attached to the back of motherboard B; the light emitting diode array is connected to a light emitting diode array control circuit, and the light emitting diode array control circuit controls the on and off state of each light emitting diode in the light emitting diode array. For details, see the attached Figure 4The light emitting diode array control circuit includes a single chip microcomputer U1 and M serial / parallel output shift registers ( Figure 4 U2 and U3), the single chip microcomputer is connected to the serial / parallel output shift register, M serial / parallel output shift registers are cascaded with each other, and each parallel output end of the serial / parallel output shift register is connected to a light emitting diode in the light emitting diode array through a resistor, so as to control the on and off of each light emitting diode in the light emitting diode array. Furthermore, a power switch is provided in the light emitting diode array control circuit to control the on and off of the light emitting diode array control circuit.

[0034] The front surface of the motherboard A and the front surface of the motherboard B are both smooth planes, so that the front surface of the motherboard A and the front surface of the motherboard B can be closely attached together, and each circular hole of the circular hole array of the motherboard A is opposite to each circular hole of the circular hole array of the motherboard B. In addition, since the two motherboards are closely attached together, no light leaks between the circular holes of the two motherboards.

[0035] Furthermore, the circular hole array structure is that a circular hole is opened in the middle of each side of each small square in the square grid of N rows and N columns.

[0036] Furthermore, the photoresistor network is a square grid with N rows and N columns, and a photoresistor is connected in series at the middle position of each side of each small square in the square grid.

[0037] The method of conducting the experiment using the above percolation test apparatus is as follows:

[0038] When in use, the front of motherboard A and the front of motherboard B can be closely attached together, and each circular hole of the circular hole array of motherboard A is opposite to each circular hole of the circular hole array of motherboard B one by one; the power supply of the main circuit of the photoresistor is turned on, and then the power supply of the light-emitting diode array control circuit is turned on. When the power is just turned on, all the light-emitting diodes in the light-emitting diode array are fully lit, and the photoresistors are in a low-resistance conduction state. At this time, the current flowing through the entire photoresistor network is the maximum value; then divide it according to the percentage of the number of light-emitting diodes that are extinguished to the number of circular holes in motherboard B (i.e., the occupancy probability), such as 10%, 20%, 30%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 80%, 90%, 100%, 100%, 150%, 160%, 170%, 180%, 190%, 200%, 210%, 210%, 220%, 230%, 240%, 250%, 260%, 270%, 280%, 290%, 300%, 310%, 320%, 330%, 340%, 350%, 360%, 370%, 380%, 390%, 400%, 410%, 420%, 430%, 440%, 450%, 460%, 470%, 480%, 490%, 500%, 510%, 510%, 510%, 520%, 530%, 540%, 550%, 560%, 560%, 570%, 580%, 590%, 600%, 6 0% and 100% (can be divided according to experimental needs), use the corresponding percentage (generally starting from a low percentage) to randomly turn off the light-emitting diode, and the photoresistor in the corresponding circular hole where the light-emitting diode is turned off changes from on to high resistance state. At the beginning, due to the low occupancy probability, a large current will still flow through the entire photoresistor network. As the percentage of the extinguished light-emitting diodes increases, the current value gradually decreases until the occupancy probability increases to a certain value, and the current of the entire photoresistor network drops suddenly. Due to the sharp decrease in current, the comparator in the current sudden change detection circuit is triggered to change, and the indicator light-emitting diode D1 in the current sudden change detection circuit changes from the original on state to the off state.

[0039] During the experiment, when the occupation probability is changed, the current value flowing through the entire photoresistor network at different occupation probabilities is recorded by an ammeter, the relative conductance is calculated, and the percolation threshold Pc is found by graphical method.

[0040] The above is an exemplary description of the present invention. It should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacement that can be done by other technical personnel in this field without expending creative labor falls within the protection scope of the present invention.

Claims

1. A percolation test apparatus, characterized in that: The invention comprises a motherboard A and a motherboard B, wherein a circular hole array is arranged on the motherboard A, a photoresistor is embedded in each circular hole of the circular hole array, the photoresistors are connected by wires to form a photoresistor network, the photoresistor network is electrically connected to a photoresistor main circuit, a DC power supply, a sampling resistor and a current sudden change detection circuit are arranged in the photoresistor main circuit, and the current sudden change detection circuit is connected in parallel to both ends of the sampling resistor; A circular hole array consistent with that of the motherboard A is arranged on the motherboard B, and a light emitting diode is embedded in each circular hole on the motherboard B. These light emitting diodes are electrically connected to a printed circuit board to form a light emitting diode array, and the light emitting diode array is electrically connected to a light emitting diode array control circuit; The front side of motherboard A and the front side of motherboard B are attached together, so that each circular hole of the circular hole array of motherboard A is opposite to each circular hole of the circular hole array of motherboard B one by one.

2. The percolation tester according to claim 1, characterized in that: The front surface of the motherboard A and the front surface of the motherboard B are both smooth planes.

3. The percolation tester according to claim 1, characterized in that: The circular hole array is a circular hole formed in the middle of each side of each small square in a square grid of N rows and N columns.

4. The percolation tester according to claim 1, characterized in that: The photoresistor network is a square grid with N rows and N columns, and a photoresistor is connected in series at the middle position of each side of each small square in the square grid.

5. The percolation tester according to claim 1, characterized in that: A power switch and an ammeter are arranged in the main circuit of the photoresistor.

6. The percolation tester according to claim 1, characterized in that: The current sudden change detection circuit is provided with an indicating light emitting diode.

7. The percolation tester according to claim 1, characterized in that: The current sudden change detection circuit includes a comparator, a resistor R1, a resistor R2, a resistor R3 and an indicating light emitting diode, one end of the sampling resistor is connected to the inverting input end of the comparator, the other end of the sampling resistor is connected to the GND end of the comparator, the resistor R1 and the resistor R2 are connected in series between the VCC end and the GND end of the comparator, and the connection point between the resistor R1 and the resistor R2 is connected to the non-inverting input end of the comparator, and the resistor R3 and the indicating light emitting diode are connected in series between the VCC end and the output end of the comparator.

8. The percolation tester according to claim 1, characterized in that: The connecting wires of the photoresistor network are adhered to the back of the motherboard A through organic silica gel; a bottom plate is also arranged on the back of the photoresistor network.

9. The percolation tester according to claim 1, characterized in that: The light-emitting diode array control circuit includes a single-chip microcomputer and M serial / parallel output shift registers, the single-chip microcomputer is connected to the serial / parallel output shift registers, the M serial / parallel output shift registers are cascaded with each other, and each parallel output end of the serial / parallel output shift register is connected to a light-emitting diode in the light-emitting diode array through a resistor.

10. The percolation tester according to claim 1, characterized in that: The light emitting diode array control circuit is provided with a power switch.

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